HexB-/- mice display many phenotypic similarities to humans afflicted with Sandhoffs disease. In this study, manganese-enhanced MRI (MEMRI) was used for the first time to measure blood-brain barrier (BBB) integrity the hexB-/- mice. 5 young hexB-/- mice and 5 old hexB-/- mice as well as age-matched controls were imaged in-vivo post intraperitoneal administration of MnCl2 to assess the leakiness of the BBB.